Tuesday, September 20, 2005

The Reality of Spaceflight

It has been said that once you get to orbit, you're half-way to anywhere. For example, it takes comparable amounts of energy to go from orbit to the Moon or to Mars. It has also been said that the first step, getting to orbit, is a bitch. That one needs to be said more often.

In The Cold Equations Of Spaceflight, Jeffrey F. Bell responds to some of the critics of NASA's "Back to the Future" plan for the Moon, Mars, and Beyond initiative. These are the critics asking "Where is the sexy new stuff? For that matter, where is the sexy old stuff like the X-30/NASP, DC-X/Delta Clipper, or X-33/VentureStar?"

In the 80's and 90's NASA and the US military spent billions working on next-generation spaceship designs. Most were reusable Single Stage To Orbit (SSTO) designs and every project was a failure. These failed projects and the Shuttle program proved that there is only one viable launch configuration: a multi-stage rocket with the payload on top.

There are other possibilities for getting into space but they are far from what the general public imagines and they are much slower than rockets, both taking days to reach orbit. They also have significant technical hurdles which must be overcome and even with unlimited funding, neither will be carrying humans into space before 2020. These possibilities are JP Aerospace's Airship-To-Orbit concept and LiftPort's Space Elevator.

Although many view NASA's new Moon plan as a return to the past, it is really a return to sanity and this cannot be emphasized enough. This reality must be accepted before we can move on.